"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Haliburton JC, Vesonder RF, Lock TF, Buck WB.Signs and lesions characteristic of equine leucoencephalomalacia were produced in one of two donkeys given corn cultured with Fusarium moniliforme Sheldon. Gross and histopathologic lesions of the cerebrum included an extensive necrotic cavitation within one cerebral hemisphere, disruption and rarefication of the subcortical white matter, prominent perivascular hemorrhage, and some mononuclear cell perivascular cuffing. Another donkey and three rabbits fed the cultured corn did not develop characteristic signs or lesions of the toxicosis. Chick bioassay studies indicated that the cultured corn...
Merkt H, Günzel AR.Embryonic resorption is reported as the main reason for early pregnancy losses in the West German Thoroughbred mare. An analysis of breeding records for the last 11 years showed a resorption rat of 8.4 per cent. Evidence was obtained that these early embryonic losses were associated with too early conception after foaling and with the state of lactation.
Thornton JR, Lohni MD.Lactic dehydrogenase, although widely distributed in most tissues, was more highly concentrated in skeletal muscle, cardiac muscle, kidney and liver. Isoenzyme patterns showed a selective concentration of LDH5 in skeletal muscle while in the heart LDH 1 and 2 were predominant. In contrast, creatine kinase was only present in substantial concentration in skeletal and cardiac muscle. The serum concentrationof both enzymes showed a wide range of activity.
Splitter GA, Incefy G, Iwata T, McGuire TC.Arabian horses with severe combined immunodeficiency disease (SCID) were evaluated for thymic hormone activities using thymic extracts and sera. Extracts prepared from thymus of SCID horses were able to increase the number of spleen cells responding to sheep red blood cells in irradiated, bone marrow-reconstituted mice. In addition, ultrafiltrates prepared from sera of these immunodeficient horses, which contained material with molecular weight of less than 50,000 Daltons could (a) induce a population of human bone marrow precursor cells to differentiate into cells bearing SRBC receptors and f...
Summers PM, Wells KE, Adkins KF.The features of an ossifying ameloblastoma in a 5-year-old gelding are described. The tumour developed in the angle of the right mandible and microscopically consisted of multiple follicles and islands of epithelial tissue adjacent to which were trabeculae of bone, osteoid and compact collagenous tissue.
Bistner SI, Riis RC.Several manifestations of equine corenal ulcers caused by mycotic agents are discussed. Antifungal therapy is reviewed. Mycotic keratitis should be suspected when routine corneal ulcer therapy is nonproductive.
Stromberg B.There appears to be an increasing incidence of osteochondrosis in young fast-growing horses in Europe and the USA. The disease is thought to be congenital in type and affects endochondral ossification in growing bones. It can be localised to one joint or may be a generalised condition. The clinical manifestations of the disease lead to a secondary chronic degenerative joint disease in adult animals. There is a genetic predisposition to the condition which is associated with rapid growth and excessive high energy feeding. The careful genetic selection of bloodstock and restricted intake in earl...
Arnbjerg J.After a short review of previous literature about fractures of the navicular bone in horses, the symptoms and the pathological-anatomical changes of the condition are described. The most important clinical symptom is acute severe lameness without significant swellings, but with pronounced pain reaction to rotation of the coffin joint. After rest the lameness is reduced considerably, but without treatment it can persist for several years. Adherences between the deep flexor tendon and the site of the fracture and eventual damage to the coffin joint are considered to be the cause of the persistin...
McKenzie RA, Blaney BJ, Gartner RJ, Dillon RD, Standfast NF.Standardbred geldings were used in a number of nutritional balance experiments. These consisted of 28-day cycles each of an 18-day equilibration period in yards and a 10-day settling and collection period in metabolism crates. The crates were made of galvanised metal tubing over wooden flooring covered by rubber matting and rubber sheets. Total faeces were collected in trays at the rear of crates and total urine by canvas funnels slung beneath the sheath of each horse.
El Sanousi SM, El Tayeb Amna B, Shadad EY.Uterine washes collected from 200 barren mares were examined at the Khartoum veterinary clinic during the period May 1977 to May 1978. A variety of bacteria was isolated from 77 per cent of the mares investigated. Thirty mares were treated by parenteral injection and intrauterine infusion of the appropriate antibiotics. Twenty-one of these mares conceived, of which 17 delivered normal foals and 4 had early embryonic deaths.
Svendsen CK, Hjortkjaer RK, Hesselholt M.42 horses were examined. The physical signs with relation to circulatory insufficiency and the abdominal disease were registered following a two-phased examination procedure. Great prognostic value was found in the degree of circulatory insufficiency judged by pulse rate and character, filling of the jugular vein, skin temperature, colour of mucous membranes, capillary refill time, sweating, depression, skin turgor and degree of enophthalmus. In making a causal diagnosis the abdomen was examined for shape, tenderness, peristaltic sounds, gastric dilation by siphoning, abnormal rectal findings ...
Voith VL.Desensitization (gradually exposing an animal to a fear-inducing stimulus without evoking the fear response) and counter-conditioning (rewarding the animal for behavior incompatible with the fear response) are highly successful ways of eliminating or reducing fear responses and corresponding aggression.
Hunt JP, Haywood PE, Moss MS.A gas chromatographic screening procedure for the non-steroidal anti-inflammatory group of drugs is described. The method invovles on-column methylation of the carboxylic acid group using trimethylanilinium hydroxide as the methylating reagent. Fifteen such drugs were studied. Eight of these were detected in urine collected from horses that had received these compounds orally and for these drugs, rates of urinary excretion are recorded. Seven other members of this group of drugs were shown to be detectable by this procedure but in these cases the drug was added to urine and not administered to...
Benson GJ, Hartsfield SM, Smetzer DL, Thurmon JC.Succinylcholine chloride, administered to horses anesthetized with halothane in oxygen and mechanically ventilated, caused slight but significant (P less than 0.01) increases in heart rate. Significant alteration in mean arterial blood pressure did not occur, and there were clinically insignificant increases in serum K+ and C1- concentration. Cardiac dysrhythmia and myoglobinuria did not occur. Thus, effects of halothane anesthesia and mechanical ventilation prevented cardiac dysrhythmia and hypertension and greatly reduced the tachycardia generally associated with siccinylcholine administrati...
Brown CM, Holmes JR.The paper discusses the various parameters which are currently used in attempts to assess the contractile efficiency of the myocardium in various species. These procedures depend upon accurate recording of intracavity pressure. The response of a catheter-mounted microtransducer compared with a fluid-filled catheter manometer system is illustrated to show the advantage of the former in providing a true representation of pressure changes.
Hartley WJ, Dixon RJ.Twenty-nine cases of EHV1 infection occurred on a property, mainly in full term foals. Some foals were stillborn, some were born alive but weak and soon died and others were healthy at birth, became ill and died within 3 days of birth. Apart from voluminous, oedematous and atelectic lungs there were no gross lesions. Microscopically the lungs showed oedema, pneumonitis and bronchiolitis with intranuclear inclusions and, in many of the foals that survived over 6 hours, there was also hyaline membrane formation. Microscopic lesions were also seen in the liver, adrenal, thymus and spleen of some ...
Muir WW, Skarda RT, Sheehan WC.The cardiopulmonary effects of two xylazine-morphine sulfate drug combinations (mixtures) given IV were evaluated in horses. In horses given xylazine (0.66 mg/kg of body weight) and morphine sulfate (0.12 mg/kv) IV (experiment 1), there were significant (P less than 0.05) decreases in heart rate, cardiac output, and respiratory rate. Central venous pressure was significantly (P less than 0.05) increased. Arterial and pulmonary arterial blood pressures increased significantly (P less than 0.05) but transiently. Arterial blood gas tensions (PaCO2 and PaO2) and pH remained unchanged. In the horse...
Roberts MC, Norman P.The absorption of d-xylose forms the basis of a useful screening test in the investigation of small intestinal disorders in the horse. A comparison has been made of different assay methods and there was no significant difference between the results obtained with the parabromoaniline (PBA) method or the ferric chloride-orcinol (FCO) method. The orthotoluidine method was unsatisfactory. The anticoagulant agent did not affect the test. A dose of 0.5 g commercial grade xylose/kg body weight as a 10 per cent solution given by stomach tube, produced a peak plasma xylose level after 90 min and should...
Henry RW, Diesem CD, Wiechers DO.Eleven ponies and 13 horses were used to develop a technique for determining conduction velocity for the radial and median nerves and establishing normal limits for these values. One pony was euthanatized to determine the course of the radial and the median nerves. From this dissection, both proximal and distal stimulation sites for the radial and the median nerves were selected, as well as areas for recording muscle evoked responses from the abductor digiti I longus (extensor carpi obliquus) and the radial head of the deep digital flexor muscles. The other ten ponies and the horses were used ...
Gummow B, Herr S, Brett OL.A microtitration serum agglutination test, based on that used for brucellosis, has been developed to detect antibodies in the sera of horses exposed to the contagious equine metritis (CEM) organism. Two known positive sera were tested 100 times in 15 separate tests. The results were reproducible to within a twofold range. The test is capable of being carried out within 100 min.
Smanik LE, Stefanovski D, Reilly PT, Richardson DW.Type II distal phalanx (P3) fractures are a well-described cause of lameness in horses. Reports on outcome following internal fixation of type II P3 fractures are lacking, and with little emphasis on complications. Objective: To describe a technique for internal fixation of type II P3 fractures, and evaluate whether specific variables influenced post-operative complications or a horse's ability to return to work. Methods: Retrospective case series. Methods: Medical records of 51 horses with CT-guided internal fixation of type II P3 fractures were reviewed. Outcome data were acquired from race ...
Dodman NH, Lehr JL, Spaulding GL, Gavriely N.Three sheep, a foal, a pony, and a calf were anesthetized and ventilated for short periods, using a high-frequency oscillatory ventilator. The efficiency of CO2 elimination was characterized at various oscillatory frequencies (50 to 30 Hz) and various tidal volumes, although the tidal volume used was always less than the measured dead space of the animal. In general, increasing either the oscillatory frequency or tidal volume increased CO2 elimination, but increasing the tidal volume had more effect. The relationship between these 3 variables was best described by a power law equation. Ventila...
Finley MR, Rebhun WC, Dee A, Langsetmo I.An 8-year-old castrated male Paint Horse was referred because of generalized pruritus, alopecia, and intermittent fever. Results of gross evaluation of the skin and microscopic evaluation of skin scrapings were inconclusive. Histologic examination of skin biopsy specimens revealed vasculitis. The horse had persistent hypercalcemia; therefore, lymphosarcoma was considered a possibility. Ultrasonography revealed hypoechoic nodules within the parenchyma of the spleen and liver. Results of microscopic evaluation of an aspirate from a splenic nodule were suggestive of lymphosarcoma. The condition o...
Luiz MA, Senna D, Padilha FGF, Nogueira WA, Fonseca AB, de Mello MFV, Ferreira AMR.The aim of this study was to perform linear measurements and assess morphometric indices of equines of the Pantanal race of different ages in the municipality of Poconé-Mato Grosso. Fifty-seven clinically healthy male and female horses between 1 and 19 years of age were selected and divided into groups by sex: 41 animals males and 17 animals femeles, and age groups: group 1 (nine animals up to 12 months of age), group 2 (eight animals from 12 to 24 months), group 3 (15 animals from 24 to 48 months), and group 4 (27 animals older than 48 months). With the aid of a hypometer, the following...
Yovich JV, Aanes WA.A fracture of the caudal portion of the greater tubercle of the humerus was diagnosed in a 16-month-old Thoroughbred filly. Initially the fracture caused severe lameness. Radiography of the affected shoulder revealed the fracture fragment to be extra-articular, with a surrounding bony callus and no evidence of joint disease. After 5 weeks rest in a stall and 11 months at pasture, the filly was trained and raced without lameness.
Spurlock GH.Seemingly, propagation of a dorsal cortical fracture in the third metacarpal bone developed after continued race performance in 2 horses. Historically, both horses had intermittent lameness that had responded to nonsteroidal anti-inflammatory drugs and brief rest periods. However, lameness in both horses had increased in severity. Radiography revealed a dorsal cortical fracture of the third metacarpal bone, with propagation of the fracture plane proximally. Fractures were incomplete and healed with stall rest in both horses.
Miragliotta V, Lefebvre-Lavoie J, Lussier JG, Theoret CL.Horses suffer from a debilitating impediment in repairing wounds located on the lower limb that leads to the development of a fibroproliferative disorder (exuberant granulation tissue). This condition is a source of wastage since it often forces retirement from competition. Treatments that resolve or prevent this condition are still lacking, maybe due to deficient knowledge of the underlying molecular mechanisms. Fibroblast-to-myofibroblast conversion is an essential step allowing contraction during wound repair and is accompanied by an increase in OB-cadherin expression. Objective: To clone e...
Heap RB, Hamon MH, Allen WR.Aromatase distribution in membranes of preimplantation horse and donkey conceptuses was compared by measuring the incorporation of [3H]androstenedione into oestrone and oestradiol-17 beta. In the donkey conceptus, aromatase activity was similar in all the tissues examined (yolk sac, chorionic girdle and allantochorion), whereas in the horse it was generally lower and showed the relationship chorionic girdle greater than yolk sac greater than allantochorion. A higher proportion of labelled precursor was incorporated into oestradiol-17 beta by extra-embryonic tissues of the donkey compared with ...
Phillips AW, Woodrooffe JG, Courtenay JS, Whitaker AM, Thomas D, Woiwod AJ.Antibodies to cultured human lymphoblasts were raised in horses using a schedule employing both subcutaneous and intravenous routes of injection. Plasma from groups of horses was pooled and the IgG prepared from each pool was tested extensively for safety and immunosuppressive efficacy in vitro and in vivo. On the basis of the results of skin grafting in monkeys, only globulins derived from the first main bleeds were blended to produce a bulk for clinical use. One early pool of globulin was discarded because when undiluted, it was lethal in monkeys by the intravenous route, and another pool wa...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Fašmon Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the fruit of L. (dill tincture) when used as a sensory additive in feed and water for drinking for all animal species. The product is a ■■■■■ solution, with a dry matter content of approximately 0.9%. The product contained 0.0247% polyphenols (of which 0.0137% were flavonoids) and 0.003% carvone. Estragole was present at concentrations between the limit of detection and the limit of quantification in the five batches examined. The Panel on A...
Pellegrini A, von Fellenberg R.Pre-alpha 2-elastase inhibitor of horse plasma has recently been isolated in our laboratory. In this article we demonstrate that the inhibitor is a composite structure built of alpha 1-proteinase inhibitor and alpha 1-beta 1-glycoprotein. The compound inhibitor is biologically active, although it has previously been shown that its enzyme specificity is different from that of free alpha 1-proteinase inhibitor. Our observations are based on immunochemical cross-reactions between pre-alpha 1-elastase inhibitor and antibodies to alpha 2-beta 1-glycoprotein as well as antibodies to alpha 1-proteina...
Earing JE, Lawrence LM, Hayes SH, Brummer M, Vanzant E.The ability of young and mature horses to digest DM, OM, and NDF was compared using 6 weanling colts and 6 mature (13.2 ± 3.0 yr) geldings. Each colt was paired with a gelding, and the pair was adapted to a diet containing 67% alfalfa cubes and 33% concentrate for 21 d. During the adaptation period, horses were accustomed to housing and all handling procedures. The adaptation period was also used to adjust the amount of feed offered to minimize orts and to maintain similar rates of intake within a pair. After the adaptation period, a 5-d fecal collection period using fecal collection harnesse...
Tuska P, Tóth B, Vásárhelyi G, Hangody L, Papp M, Bodó G.The purpose of this study was to evaluate changes in biomarker and synovial parameters following autologous osteochondral transplantation (AOT) in the equine stifle joint, to test the hypothesis whether synovial parameters would show significant differences at selected time points following the surgery (at days 3, 14, 60 and 180) compared to baseline level (at day 0). Surgical intervention was performed in both stifles of nine horses (n = 18). The joints were randomly assigned to operated and sham-operated groups. Grafts 8.5 mm in diameter were harvested from the femoropatellar (FP) joint unde...